Stochastic particle motion and anomalous thermal conductivity in a tokamak
Parail V. V., Yushmanov P. N.
A self-consistent theory is derived for the spatial diffusion of electrons in electromagnetic fluctuations of arbitrary amplitude in a tokamak. Toroidal drift is taken into account. The diffusion is determined by banana electrons with a scale time r~qR /vey[efor the onset of a stochastic motion. The scale length of the diffusion which is nonlinear in the wave amplitude reaches saturation at a level ~2cV<»J + v2eq2/t>2He€.